• PNG police with dogs asked to enter detention centre on 17 February• Guard’s statement written morning after riot names Reza Barati• Official incident log says G4S ‘lost control’ of local riot squad• ‘No Australian will tell us what to do,’ one local said

The Papua New Guinean police dog squad was invited into the Manus Island detention centre under instruction from a senior G4S guard before a riot erupted on 17 February, according to a graphic statement seen by Guardian Australia.

The statement of a guard, employed by the security contractor G4S which runs the detention centre for the Australian government, was written the morning after the violence and provides the most detailed description and timeline yet of how events unfolded in the Manus clashes, which left one asylum seeker dead and dozens injured.

Guardian Australia has also seen a page of what is understood to be the official “incident report” provided to the Immigration Department, which shows how G4S staff “lost control” of the local riot squad during Monday night’s unrest.

The guard’s first-hand account of the evening, of which Guardian Australia has seen a section, paints a terrifying picture of events in the buildup to the violence.

At the same time he overheard local maintenance staff just outside the centre, telling local police “this is our land and no EX-Pat Australian or New Zealander will tell us what to do on our land, if the transferees come outside of that fence line (as he pointed to Oscar [compound inside the detention centre] fence line) then we will do whatever we need to, this is our land we are in charge here … ”

The statement says the guard informed a senior G4S manager of the threatening conversation but at 9.44pm was instructed by the same manager to invite two PNG police dog squad officers into the compound.

The guard describes how events deteriorated after the PNG police entered the centre:

“As the two Police and dogs entered this area the Transferees from Mike Compound became aggressive and started throwing rocks at the dogs and Police handlers, the Police handlers and dogs attempted to stand their ground but due to the barrage of rocks they withdrew behind the fence at Gate Golf 2. The transferees continued to become more aggressive and armed themselves with pipes and covered their faces with ‘T shirts’ and continued to throw rocks at the Police and G4S Security Officers.”

The guard then says a group of around five to eight detainees pushed over an internal fence within Mike compound, where it is understood the majority of the conflict took place.

The statement was written at 8.37am the morning after the riot. That same morning the immigration minister, Scott Morrison, said: “PNG police did not enter the centre and … their activities related only to dealing with transferees who breached the external perimeter.” Five days later the minister conceded that the rioting and “response” occurred within the centre.

The guard’s statement also names Reza Barati as the asylum seeker killed during the rioting – indicating that personnel were aware of who had been killed immediately after the event. Morrison did not name Barati until four days after.

The page of the G4S incident report gives further details of how G4S managers lost control of the local riot squad. G4S confirmed to Guardian Australia that this incident log was created the day after the riot.

At 11.20pm, it says, the fence at Oscar compound was breached. “At this time,” the report says, “multiple code Greens [escapes] were reported in Oscar compound where transferees had armed themselves with improvised weapons.”

According to the report, at 11.30pm, the police mobile squad withdrew from Mike compound and the evacuation of casualties began. But the report says that at exactly the same time the officer in charge of the local G4S riot team “lost control” and members of the team “dispersed into the immediate area of Mike compound”.

At 11.37pm the official annotating events and the radio operator were evacuated from the site, “due to the ongoing risk to personnel”.

At this time asylum seekers inside Mike compound were described as “frightened and distracted” and medical staff were brought in to deal with casualties.

By 12.05am on 18 February one compound, Foxtrot, which is next to Mike compound, was completely empty.

By 1am G4S officers began to push asylum seekers back into the central Oscar compound. At this point, the report states, an officer “starts mediation with transferees to bring an end to the protest”.

It continues: “All Oscar compound Transferees in the compound and things start to settle down and by 0120 the Transferees inform G4S SS0 [Safety Security Officer] that they have finished for the night.

An eyewitness account of scenes at the Hotel Bibby, the floating accommodation block used by contractors on Manus, published by Guardian Australia on Tuesday, describes wounded asylum seekers being taken by G4S personnel on ute to a makeshift hospital.

“They were just makeshift beds. Transferees were carried in on sheets. Blood everywhere, crying,” the contractor told Guardian Australia. “There were 30 or 40 clients down there. We had gunshot wounds, some with head injuries.”

The contractor said asylum seekers who were treated by medical staff all claimed they had not been involved in the protests and some reported being dragged out of their beds in darkness and beaten.

A spokesman for G4S said: “We cannot confirm the veracity of any individual witness statements at this time. We have received numerous witness statements and they will all be made available to the Cornall review.

“We do not wish to compromise the integrity of that review by commenting on individual statements at this time.“It is not G4S’s role to provide incident reports to Minister Morrison. G4S provides these reports to the Department of Immigration and Border Protection.”

A spokeswoman for the immigration minister said: “All relevant documents will be made available to the Cornall review. It will be a matter for the review to establish the facts of the incident on Manus Island. It would not be appropriate to pre-empt the findings of the review.”